With four films opening nationwide Friday -- including one from music sensation Justin Bieber -- Valentine's Day weekend should mark the busiest frame of the year so far at theaters and help shake off the malaise that has gripped the domestic box office.

Sony's Adam Sandler-Jennifer Aniston romantic comedy Just Go With It is widely expected to open north of $30 million (some put the figure closer to $35 million) and win the weekend crown. The movie should also see a spike Monday, since that's when Valentine's Day falls. RELATED: Read THR's review of Just Go With It

Go With It opens in 3,548 theaters, while Paramount's Justin Bieber: Never Say Never goes out in 3,105 locations, including 2,516 3D runs.

Part biography, part concert film, Never Say Never is the big wild card of the weekend in terms of how much it will gross. Tracking services readily admit they have a difficult time gauging this sort of fare. Also, box office observers don't know how to assess Bieber's feverish girl fan base. RELATED: Read THR's review of Never Say Never

Never Say Never, from Paramount's Insurge Pictures banner and directed by John M. Chu, should open in between Hannah Montana/Miley Cyrus: Best of Both Worlds Concert Tour, which debuted to $31.1 million in 2008, and Jonas Brothers: The 3D Concert Experience, which opened to a much softer $12.5 million.

Paramount is hoping Bieber's film will help brand Insurge, a low-budget division designed to take advantage of social media. Never Say Nevercost $13 million to produce, a minimal spend.

Bieber's fans are generally tween and teenage girls, give or take a few years (some are as young as 7). Never Say Nevershould see hefty matinee grosses Friday as funs rush to see the pic, which has already collected roughly $2 million from 300 advance screenings Wednesday night (half of the $2 million was applied to special merchandise handed out at the shows).

One thing that could bite into Never Say Never is animated family film Gnomeo & Juliet, from Disney's Touchstone Pictures. The film is tracking particularly well among parents, who may try to convince girls to see Gnomeo instead of Never Say Never. Gnomeo also has a distinct in advantage of being the first family film since Yogi Bear. RELATED: Read THR's review of Gnomeo & Juliet

Gnomeo wasn't made by Disney, but by former specialty arm Miramax. When the studio sold off Miramax, it kept the 'toon, in large part because of Elton John, whose music is featured in the film.
This week, John has been making the rounds to promote Gnomeo, including an appearance on NBC's Today.

The fourth film opening Friday is Focus Features' Channing Tatum Roman epic The Eagle, directed by Kevin Macdonald from a script by Jeremy Brock. Film rolls out in more than 2,200 theaters and should play heavily to males. RELATED: Read THR's review of The Eagle

Tracking suggests an opening of $6-9 million. Focus didn't disclose the film's budget, but said it would be happy with a debut in the high teens. Overseas, Focus sold off rights in non-English-language territories, helping to pay for the film's production.

Macdonald wanted to make a period epic without big special effects. The Eagle was adapted from Rosemary Sutcliff's 1954 historical book The Eagle of the Ninth, about a young Roman officer's search for the truth about the disappearance of his father's legion in Britain.

Cedar Rapids has drawn strong reviews. Many critics also are tipping their hats to Gnomeo and Never Say Never.

Loosely based on the 1969 film Cactus Flower, Just Go With It is drawing less favorable notices. Marking the sixth time Dennis Dugan has directed Sandler, pic also stars Brooklyn Decker and features a cameo by Nicole Kidman.

Allan Loeb and Timothy Dowling penned the script, about a plastic surgeon that goes through life pretending he's married in order to avoid commitment. When he meets the girl of his dreams (Decker), he tells her he's getting a divorce and convinces his office manager (Aniston) to act the role of his wife.

Sandler's last romantic comedy was 50 First Dates, which opened over Valentine's Day in 2004, grossing $39.8 million (Valentine's Day fell on a Sunday that year.)

Trying to manage expectations, Sony is predicting an opening in the high 20s, although rivals put the gross higher. Sony says the film will work as a romantic comedy with women while also playing to Sandler's male fan base.

One thing all of Hollywood can agree on is the nice boost films should see a week from now, over the long President's Day weekend.